Twelve-Month Outcomes of the Prospective,Multicenter,Single-Arm Study of the 355-nm Laser for Treatment of Below-the-Knee Arteries: Final Results of the Auryon BTK

Abstract

Background:

The Auryon laser atherectomy system has been shown to have high procedural success in the prospective, multicenter Auryon BTK study. We present the 12-month outcomes of the Auryon BTK in treating infrapopliteal arterial disease in patients with chronic limb-threatening ischemia (CLTI).

Methods:

Patients at 4 US centers with CLTI were prospectively enrolled in the Auryon BTK study after obtaining informed consent. The study was approved by a central ethics committee. The 30-day primary safety and procedural success were recently published. Secondary endpoints included target lesion revascularization (TLR), clinical patency (defined as peak systolic velocity ratio ≤2.4 and no TLR), major adverse limb events (amputation, target vessel revascularization, and/or all-cause mortality), Walking Impairment Questionnaire (WIQ), Rutherford Becker (RB) category, and EQ-5D quality of life questionnaire. Proportional and Kaplan–Meier (K-M) survival analysis were performed.

Results:

A total of 60 patients (61 lesions) were enrolled. At 12-month, 42 patients were still in the study (7 lost-to-follow-up, 5 withdrawals, 7 deceased). The mean age was 74.6 ± 10.3 years with 58.3% diabetics, 43.3% RB IV, and 56.7% RB V. Of the 61 lesions, 59% had severe calcification, 31.1% were chronic total occlusions, and 90.2% were de novo disease. Bailout stenting occurred in 1/61 lesions (1.6%). Proportional analysis for freedom from TLR at 1-year was 94.2%, and TVR was 89.4%. K-M analysis for freedom from TLR was 94.0% at 12-month. There was a significant difference in median WIQ score from to baseline to 3-month (p = 0.0020) and baseline to 6-month (p = 0.0290) but not from baseline to 12-month (Δ−0.073, p = 0.678). Wounds healed in 33.3% (n = 4/12) of patients at 12-month. There was also a significant difference in median EQ-5D total score from baseline to 30-day (p = 0.0030), 3-month (p = 0.0060), 6-month (p = 0.0500), and 12-month (p = 0.00005). In addition, there was a significant median difference between 30-day ankle-brachial index (ABI) and baseline ABI (p < 0.0005) and the 12-month ABI and baseline ABI (p = 0.2100). Rutherford–Becker category improved by ≥1 category among 67.6% (n = 23/34) patients, stayed the same in 29.4% (n = 10/34) patients and worsened in 2.9% (n = 1/34) patients at 1-year.

Conclusion:

The 355-mm laser has a high rate of freedom from TLR at 12-month with a significant improvement in RB categories, WIQ and quality of life (EQ-5D).

Clinical Impact

The Auryon BTK demonstrates the safety and effectiveness of the 355-nm Auryon laser system in treating infrapopliteal arterial disease in patients with critical limb ischemia yielding high freedom from TLR and improvement in quality of life despite complex disease. The Auryon laser can treat all lesion morphologies below the knee including severe calcium and needs to be considered by operators for vessel prepping prior to adjunctive balloon angioplasty.